Treatment of porous surfaces of articles of manufacture

ABSTRACT

Porous structures, e.g., concrete, wood, cinder block, ceramics, tiles, etc. are rendered less permeable by applying, e.g., spraying or painting to their surface, an aqueous solution having a pH substantially above 7 containing polyvinyl alcohol and a compound which contains polyisocyanurate salt groups, trisubstituted isocyanurate rings and end groups selected from: isocyanate, urethane, urea and amino groups.

ilnited States Patent 1191 Argabright et al. A

[ Dec. 3, 1974 TREATMENT OF POROUS SURFACES OF ARTICLES OF MANUFACTURE Inventors: Perry A. Argabright, Larkspur; C.

Travis Presley, Denver; John A. Davis, Littleton, all of Colo.

Assignee: Marathon Oil Company, Findlay,

Ohio

Filed: Dec. 26, 1972 Appl. No.: 317,883

U.S. Cl... 117/123 C, 117/123 D, 260/775 NC Int. Cl. C03c 17/00 Field of Search 117/123 C, 123 D;

260/77.5 NC, 248 NS References Cited UNITED STATES PATENTS 6/1964 Thoma et al 117 123 D 3,573,259 3/l97l Argabright et al. 260/77.5 NC 3,64l,024 2/1972 Argabright et al. 260/77.5 NC 3,707,52] 12/1972 DeSantis ll7/72 3,736,298 5/l973 Schmit et al. 260/775 NC 3,766,086 10/1973 Argabright et al. 260/775 NC Primary Examiner.l. Travis Brown Attorney, Agent, or Firm-Joseph C. Herring; Richard C. Willson, Jr.; Jack L. Hummel 5 7 ABSTRACT 4 Claims, 3 Drawing Figures PATENHIU HEB 3 .8 52. l O U sum 2 or 2 Q Q Q5.

(S=SATURATED) CH ALKYL 5 m, Q, C3

ARALKYL ALKENE! cH' -c H=cHcH -cH cH= :-cH -CH=CHCH=CH,

POLYMERIC:

cu H (WHERE n MAY BE FROM 1 to 50) BICYCLIQ Fig. 3

, l TREATMENT OF POROUS SURFACES OF ARTICLES OF MANUFACTURE CROSS REFERENCES TO RELATED APPLICATIONS DESCRIPTION OF THE PRIOR ART A search in the U.S. Pat. Office (subclasses 166-292, -295; 252-855) and Chemical Abstracts from 1907 to date disclosed the following prior art:

Group I relating to carboxy methyl cellulose and related material; U.S. Pat. No. 2,570,892 uses aqueous solutions or dispersions or polysaccharides (MW greater than 5,000) to seal porous beds, e.g., to prevent lost circulation U.S. Pat.,No. 2,689,230 uses acid solutions of cellulose ethers for acidizing wells drilled into fractured or vuggy formations; U.S. Pat. No. 2,764,242 uses starch, natural gums, e.g., arabic, gum tragacanth, Indian gum or alkali metal salts of carboxy methyl cellulose in corrosion-reducing compositions for use in wells; U.S. Pat.' No. 2,777,818 uses carboxy methyl cellulose in scale removing compositions for gas oils; U.S. Pat. No. 2,969,322 uses carboxy methyl cellulose in well packer fluids or well completion fluids; U.S. Pat. No. 2,970,959 which teaches inhibition of calcium sulfate scale onsurfaces exposed to brine by adding to the brine carboxy methyl cellulose salts of either alkali metals or ammonium; U.S. Pat. No. 3,024,191 uses carboxy methyl cellulose in aqueous fracturing fluids capable of transporting large fracture props; U.S. Pat. No. 3,292,696 uses hydroxy ethyl cellulose in oil recovery by injecting first a nonviscous aqueous liquid into the reservoir, then 0.001 to 0.03 pore volumes of aqueous solution of hydroxy ethyl cellulosehaving a viscosity of l-l0,000 centipoises at 75F.,'and then injecting a second solution of hydroxy ethyl cellulose having a viscosity intermediate between the first two liquids injected; Hercules Cellulose Gum (Bulletin pp. 30-31) teaches that viscosity reduction occurs when divalent cations are added to cellulose gum solution and that trivalent salts form insoluble precipitates with cellulose gums;

Group II relating to acrylamideand related material: I

US. Pat. No. 2,801,984 teaches soil stabilization with alkylidene bis-acrylamides; U.S. Pat. No. 2,940,729 teaches alkylidene bis-acrylamides for stopping water seepage, drilling fluid loss and coning in oil production operations; U.S. Pat. No. 3,002,960 teaches producing polyacrylamide by polymerizing in the presence of tertiary amine plus inorganic persulfates and the use of the resulting polyacrylamides for secondary recovery of oil; U.S. Pat. No. 3,020,953 teaches flooding with'polyacrylic acid amide having a K of 75-160 where K is a measure of the degree of polymerization; U.S. Pat. No. 3,044,548 locates interfaces between salt water layers and overlying fresh water layers and injects a resin, e.g.,

N,N-methylene-bis-acrylamide; U.S. Pat. No. 3,056,766 teaches aqueous gels of bis-acrylamide polymer and water soluble metal salts and their use as soil conditions; U.S. Pat. No. 3,087,543 presents water production by treating the entire producing interval with an acrylamide carboxylic acid copolymer in oil production operations; U.S. Pat. No. 3,121,463 teaches electrically-conductive acrylamide solutions for well logging; U.S. Pat. No. 3,136,360 teaches the use of acrylamide gels mixed with filter aids, e.g., diatomaceous earths to seal off permeable zones or sections in earth formations; U.S. Pat. No. 3,152,641 teaches copolymerizing bis-acrylamide with-water soluble ethylenic monomer, e.g., acrylamide in situ in subterranean areas for the purpose of sealing such areas; U.S. Pat. No. 3,175,612 teaches polymerizing, in the formation, bisacrylamide plus ethylenic monomer in the presence of an oxidizing agent and tin; U.S. Pat. No. 3,199,588 teaches plugging of formations with aqueous bisacrylamide plus ethylenic copolymer which polymerizes slowly in place; U.S. Pat. No. 3,199,589 teaches adding ascorbic acid to bis-acrylamide plus ethylenic mixture in a well to cause polymerization in situ; U.S. Pat. No. 3,210,310 teaches bis-acrylamide plus ethylenically unsaturated monomer plus redox catalyst e.g., ammonium persulfate plus calcium chloride; U.S. Pat. No. 3,212,577 teaches the samedisclosure as U.S. Pat. No. 3,210,310; U.S. Pat. No. 3,223,161 teaches a sand consolidated with bis-acrylamide polymerized by contact with S0,; U.S. Pat. No. 3,247,900 teaches adding F-lion to bis-acrylamide/ethylenic monomer solutions to inhibit polymerizatiomthen adding F1 to permit polymerization; U.S. Pat. No. 3,288,230 teaches preventing gas loss during gas drilling operations by mixing a water soluble gum or polymer, e.g., N,N'-methylenebis-acrylamide with the drilling gas and following with a charge of a mist of water or a water-base film-forming agent; U.S. Pat. No. 3,302,717 teaches oil plus polyacrylamide polymer insoluble in water but swellable by water, and its injection to plug off water intrusion in oil production operations; U.S. Pat. No. 3,305,019 teaches adding-a water soluble high molecular weight anionic acrylamide polymer in a water solution to stimulate a gas well by modifying the properties of the well bottom sand in reducing its interference with gas flow; U.S. Pat. No. 3,036,870 teaches a gel for plugging subterranean formations, formed with polyacrylamide polymer (or copolymer) plus inorganic compound which lowers surface tension, e.g., KOI-I, NaOH, K,CO of FeCl,,; U.S. Pat. No. 3,308,885 teaches reduction of water production from formations by injecting a polyacrylamide, hydrolyzed to between 8 and percent and having a molecular weight above 200,000; U.S. Pat. No. 3,437,625 teaches aqueous alkali metal silicates plus aqueous fomaldehyde/acrylamide polymer consolidating agents for soil; U.S. Pat. No. 3,442,803 teaches reducing friction in oil wells by adding acrylamide/bisacrylamide polymer to promote flow of a water-based oil well fracturing fluid; U.S. Pat. No. 3,447,608 teaches acrylamides/Portland cement plugs having a density which is less than or equal to the drilling mud; U.S. Pat No. 3,490,533 teaches recovery of oil.by injecting polymerizable monomer, e.g., acrylic acid, acrylamide, methacrylic acid dissolved in water and containing a polymerization catalyst; then permitting the late period of the catalyst to expire to polymerize the monomer to a polymer at some distance away from the well bore; U.S. Pat. No. 3,542,044 teaches friction reducing in oil pipelines by adding to the oil aqueous polyacrylamide solutions; U.S. Pat. No. 3,543,855 teaches oil recovery utilizing viscous aqueous solutions of hydrolyzed vinyl methyl ethermaleic anhydride copolymer to which is grafted polyacrylamide.

Group III of general interest: U.S. Pat. No. 2,252,271 teaches plugging formations with mixtures of dicarboxylic acid ester and polyhydric alcohol controlling the time of polymerization by addition of a benzolyl peroxide catalyst; U.S. Pat. No. 2,348,484 teaches sealing off porous formations by injecting solutions of acaroid resin in water miscible solvent; U.S. Pat. No. 2,527,581 teaches injection of a liquid resin, e.g.-, phenolic resin, normally stable at room temperature into a water permeated zone where the'resin hardens to form a barrier; U.S. Pat. No. 2,757,737 teaches forming a mixture of a hydratable material, e.g., bentonite clay, a binding agent, e.g., polyvinyl acetate, a water miscible solvent, e.g. water miscible alcohols, ketones, or esters, and introducing the mixture into a well bore adjacent to a lost circulation zone, then contacting the mix ture with water to hydrate the material and form a barrier; U.S. Pat. No. 2,819,239 teaches compositions for cementing wells comprising Portland cement, a latex of a vinylidene chloride copolymer containing acrylonitrile, vinyl chloride, or vinyl acetate and a non-ionic wetting agent; U.S. Pat. No. 3,067,161 teaches viscous compositions containing a water soluble thickening agent, e .g., a monoalkenyl aromatic sulfonate of a monalkenyl aromatic polymer having a specified formula; U.S. Pat. No. 3,1 14,419 which teaches formation plugging by subjecting an aqueous mixture of alkylidene bis-acrylamide and an ethylenic monomer to radioactivity to cause the mixture to polymerize; U.S. Pat. No. 3,116,264 which teaches improved hydraulic cement compositions containing an aqueous slurry of hydraulic cement mixed with a copolymer of maleic anhydride with N-vinyl 5- or 6-numbered ring compounds of specified structure, e.g., N-vinylpyrrolidone; U.S. Pat. No. 3,475,334 which teaches fracing fluids containing water and alcohol, together with a dialdehyde surfacetreated cellulose ester to lower the loss of fluid to the formation and achieve fracturing at lower injection rates; and U.S. Pat. No. 3,446,795 which teaches cellulose esters of improved brine tolerances characterized by carboxy-methyl MS of 0.2-1.2 and hydroxy alkyl MS of 1.5-5.

SUMMARY OF THE INVENTION General Statement of the Invention According to the present invention, specific gels formed by reaction at a pH above 7 of polyvinyl alcohol and a polyisocyanurate salt, the general formula specitied in FIG. 1, are applied to a porous surface, e.g., concrete, wood, cinder block, ceramics, tiles, rock surfaces, etc. to render them substantially less permeable to penetration by fluids. This invention relates to a new class of compositions (described also in copending United States patent application Ser. No. 260,843, filed June 8, 1972), which are useful as gels. These compositions are produced by contacting polyvinyl alcohol with compositions containing in a single molecule the following groups:

0 metal lsocyanurate,

O isocyanurate The gelling agents of the present invention have the advantage of giving a controllable time to onset of gelation. That is, by merely adjusting the pH of the initial solution, the gelation time may be controlled, a feature not available with conventional systems.

The isocyanurate compounds of the present invention have the general structure shown in FIG. 1: where:

R divalent hydrocarbon or substituted hydrocarbon radical, as described below and exemplified in FIG. 2.

X a metal or hydrogen or quaternary ammonium (which, for the purposes of this invention, acts like a metal) or a combination thereof. Particularly preferred are hydrogen, quaternary ammonium and metals selected from the following groups of the Periodic Table; 1a, 1b, Ila, 11b, Illa, IlIb, IVa, IVb, Va, Vb, VIa; including such metals as Li, Na, K, Rb, Cs, Ag, Au, Be, Mg, Ca, Sr, Ba, Ra, Zn, Cd, Hg, B, Al, Sc, Y, La, and the other rare earths, Ac, Ga, In, Tl, Ti, Zr, Hf, Ge, Sn, Pb, V, Nb, Ta, Sb, Bi, Cr, Mo, W, Mn, Fe, Ru, Co, Ni, Rh, Pd, Os, and Ir.

A a monovalent organic radical selected from the following: isocyanate (-NCO), urethane (-NI-ICO R),

urea (-NI-ICONl-IR'), amino (-N1-I N1-IR, -NR or R, for example.

R monovalent hydrocarbon or substituted hydrocarbon radical, as discussed below;

M average number of trisubstituted isocyanurate rings and is a positive number from 0 to about 400, and most preferably from 0 to about 200.

N average number of isocyanuric acid and/or isocyanurate salt groups and is a positive number from above 1 to about 10,000, more preferably from 2 to about 1,000, and most preferably from 3 to about 100.

2M+N +1 average number of divalent R groups and is a positive integer from 2 to about 11,000, more preferably from 3 to about 1,100 and most preferably from 4 to about 140.

M+2 average number of A groups and is a positive integer from 2 to about 2,000, more preferably from 2 to about 400, and most preferably from 2 to about 200;

and wherein there are no N-to--N bonds and no A- to-N bonds and no Ato-A bonds and no Rto R bonds.

R preferably contains 2 to 40, more preferably 2 to 30, and most preferably 2 to 18 carbon atoms.

R preferably contains 1 to 40 carbon atoms, more preferably 1 to 20 carbon atoms and most preferably 1 to carbons, for example, CI-I -C H C H-,, 3 1,

3 3 -CH2CH2OH, CH3- '|.-CH2-, CH2

CH-CH2-, 11 etc.

R and/or R can be substitutedwith groups that do not interfere in the products subsequent utility or in its preparation. Examples of such non-interfering groups are: --NO:, Cl, F, Br, 1, 'CN, CO R", COR", -O--R", SR", -NR CONR --SO R, SO:, --SO, phenyl, naphthyl, alkyl l-40 carbon atoms), PO R", cyclohexyl, cyclopropyl, -OCOR",

H l -oco NCOR" etc. where R" may be hydrogen, lower alkyl (e.g., ethyl, hexyl) or amyl (e.g., monovalent radicals corresponding to the aryl radicals described in FIG. 2). The examples of R (shown in FIG. 2) are set forth for purposes of elucidation, not restriction.

It will be recognized that the values of M and N described above are on the basis of the integers which will be used to describe a single molecule. In actual practice, the invention will involve mixtures of molecules of the general form described above. Thus, the average value of M for the mixture may be from about 1 to about 2,000, morev preferably from about 1 to 400, and most preferably from about 1 to 200; the average value of N may be from about'0.5 to 10,000, more preferably from about 0.5 to 1,000, and most preferably from about 0.5 to 100.

Utility of the Invention As stated above, the present invention may be utilized for the sealing of a wide variety of porous surfaces. The invention is also valuable for the consolidation of loose surfaces, e.g., sands, powdered limestone, and the like. The porous surfaces whether consolidated or unconsolidated, may be present in a variety of practical situations, e.g., the'porous surface may be the exterior wall of a basement.

Application of the ungelled-liquid can readily be ac complished by spraying, pouring,'sprinkling, brushing, rolling, or any of a wide variety of other conventional techniques for application of liquids to surfaces utilizing either especially designed equipment or conventional equipment as desired.

DESCRIPTION OF THE DRAWINGS FIG. 1 shows the general formula of the polyisocyanurate starting materials of the present invention.

FIGS. 2 and 3 exemplify some of the possible structures of R groups of a polyisocyanurate starting material and products of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Starting Materials: The gels of the present invention can be formulated according to the aforementioned Ser. No. 173,892 filed Aug. 23, 1971. The techniques of this and the other related applications, all of which are to be considered as incorporated herein, can be utilized with the present invention.

The starting materials for the present invention are Salts of polyisocyanuric acids: These are produced according to the techniques taught in US. Pat. No. 3,573,259, by reactinga metal cyanate and an organic diisocyanate in the presence of an aprotic solvent to form isocyanurate-containing polyisocyanate metal salts. Preferably 0.5 to about percent by weight, more preferably 1.0 to about 25 percent by weight, and most preferably 2.0 to about 10 percent by weight of such salts are employed in formulating the gels. Polyvinyl alcohol: The polyvinyl alcohol used in the present invention can be of commercial quality such as that marketed by Monsanto Company of St. Louis, Missouri, under the trade-name Gelvatol. It should have a molecular weight within the range of from about 2,000 to about 250,000, more preferably from 3,000 to about 200,000, and most preferably from 10,000 to about 126,000. In general, about 1.0 to about 10.0, more preferably 2.0 to about 6.0, and most preferably 3.0 to about 5.0 percent by weight of polyvinyl alcohol -will be contacted with the aforementioned isocyanurate salt starting materials. Bases: While not narrowly critical, the bases employed with the present invention will preferably be alkali -metal hydroxides, e.g., NaOI-I, KOH, LiOI-I, and alkaline earth metal hydroxides, e.g., Ca(OI-I) etc. The alkali metal hydroxides will be more preferred, with sodium hydroxide being the most preferred of the bases. In general, the pH will be adjusted into a range above 7, .more preferably from about 7.5 to about 15, and most preferably from about 12 to about 15.

Reaction Media: Water or mixtures of water and an alcohol, ketone, ester, amide, sulfoxide, sulfone, etc. can

temperature. The time is preferably from 0.01 to 4800,

more preferably 0.05 to 350, and most preferably about 0.06 to about 200 hours.

EXAMPLE I Preparation of Polyisocyanurate salt A 3-liter, four-necked glass reactor, equipped with a motor-driven stirrer, reflux condenser, thermometer and adaptor for introducing liquid is charged with 82.4 grams of potassium cyanate (1.01 moles) and 2 liters of anhydrous dimethylformamide. To the resulting slurry at 75 F, 131 ml of tolylenediisocyanate (0.925 mole) is added dropwise at a rate of 0.428 ml per minute by means of a motor-driven syringe pump, After the addition is complete, the mixture is allowed to react an additional minutes, 300 ml of methanol added, the temperature permitted to drop to room temperature (23C.) and allowed to stir an additional 48 hours. The desired product is collected by filtration of the crude reaction mixture, extracted with acetone in a Soxhlet apparatus and dried to give 250.6 grams of a white solid. The polyisocyanurate salt product is water soluble but relatively insoluble in hydrocarbon solvents. The ratio of aromatic rings to end groups,

EXAMPLE II A tank is constructed of porous concrete blocks of the usual commercial size and shape, held together with a conventional mortar. The tank is filled to a depth of approximately 2 feet with water and the water is observed to seep out through the blocks wetting them on both the interior and the exterior surfaces. The remaining water is removed from the tank, the blocks are allowed to dry, and are then treated on their interior surfaces with a solution of 3 percent polyisocyanurate salt as prepared in Example I, 4 percent polyvinyl alcohol (a 4 percent solution of the polyvinyl alcohol as used herein has a viscosity in the ranges of 28 to 32 centipoises at 20C.) and a 4 percent sodium hydroxide in water by spraying After 24 hours, the blocks are rendered substantially impervious to seepage of water from the interior of the tank. When the tank is refilled the exterior of the block remains visibly dry and so also do the interior surfaces. No significant loss of water by seepage through the walls is observed.

MODIFICATIONS OF THE INVENTION It should be understood that the invention is capable of a variety of modifications and variations which will be made apparent to one skilled in the art by a reading of the specification and which are to be included within the spirit of the claims appended hereto.

What is claimed is:

1. In a process for the sealing of porous surfaces of articles of manufacture to reduce their permeability to fluids, the improvement comprising:

a. preparing an aqueous solution containing a water soluble salt of a polyisocyanuric acid and polyvinyl alcohol or hydroxyethyl cellulose,

b. adjusting the pH of said aqueous solution as desired for a given application, always having a pH in excess of 7, and

c. applying said aqueous solution to said porous surfaces and maintaining contact between said porous surfaces and said aqueous solution for a time sufficient to permit gelation within the void space of said permeable surfaces, wherein said isocyanurate salt has the structure:

r j r w ZMtN-H M+2 wherein R divalent hydrocarbon radical X a metal, hydrogen, quaternary ammonium or a combination thereof,

A= monovalent group selected from the following: isocyanate, urethane, urea, amino, NI-I CO R',

R monovalent hydrocarbon radical M average number of trisubstituted isocyanurate rings, a positive number from 0 to about 400,

N average number of isocyanuric acid or derivative rings, a positive number from above I to about 10,000,

2M+N+1 average number of divalent R groups M+2 average number of A groups.

2. An article of manufacture comprising porous surface having void space, said void space being at least partially filled by the process of claim 1.

3. A process according to claim 1 wherein said water soluble polymer comprises polyvinyl alcohol.

4. A process according to claim 1 wherein said water soluble polymer comprises hydroxy ethyl cellulose. 

1. IN A PROCESS FOR THE SEALING OF POROUS SURFACES OF ARTICLES OF MANUFACTURE TO REDUCE THEIR PERMEABILITY TO FLUIDS, THE IMPROVEMENT COMPRISING: A. PREPARING AN AQUEOUS SOLUTION CONTAINING A WATER SOLUBLE SALT OF A POLYISOCYANURIC ACID AND POLYVINYL ALCOHOL OR HYDROXYETHYL CELLULOSE, B. ADJUSTING THE PH OF SAID AQUEOUS SOLUTION AS DESIRED FOR A GIVEN APPLICATION, ALWAYS HAVING A PH IN EXCESS OF 7, AND C. APPLYING SAID AQUEOUS SOLUTION TO SAID POROUS SURFACE AND MAINTAINING CONTACT BETWEEN SAID POROUS SURFACES AND SAID AQUROUS SOLUTION FOR A TIME SUFFICIENT OT PERMIT GELATION WITHIN THE VOID SPACE OF SAID PERMEABLE SURFACES, WHEREIN SAID ISOCYANURATE SALT HAS THE STRUCTURE:
 2. An article of manufacture comprising porous surface having void space, said void space being at least partially filled by the process of claim
 1. 3. A process according to claim 1 wherein said water soluble polymer comprises polyvinyl alcohol.
 4. A process according to claim 1 wherein said water soluble polymer comprises hydroxy ethyl cellulose. 